Cooling system for needle cylinders of circular knitting machines

ABSTRACT

A circular knitting machine having a needle cylinder is provided with means for cooling the needle cylinder by circulating oil or other cooling medium around an interior part of the needle cylinder and collecting the cooling medium while preventing it from gaining access to the exterior of the needle cylinder.

United States Patent [191 Wright et al.

[11] 3,802,223 [4 1 Apr. 9, 1974 COOLING SYSTEM FOR NEEDLE CYLINDERS OF CIRCULAR KNITTING MACHINES Inventors: Kenneth Wright, Coalville; David Greenwood, The Oval, both of England The Bentley Engineering Company Limited, Leicester, England Filed: Dec. 27, 1971 Appl. No.: 212,261

Assignee:

Foreign Application Priority Data Jan. 9, 1971 Great Britain 01131/71 US. Cl 66/8, 66/14.9 5 Int. Cl D04b 9/00 Field of Search 66/8, 1 R, 149 S;

[56] References Cited UNITED STATES PATENTS 3,078,960 2/1963 Minton 66/8 3,500,661 3/1970 Kohler et al. 66/8 2,692,473 10/1954 Birkigt 57/134 UX 3,031,991 5/1962 Hacklander.... 112/256 2,096,343 10/1937 Sauer 112/256 Primary Examiner-W. C. Reynolds Assistant Examiner-Andrew M. Falik Attorney, Agent, or Firm-Paul & Paul 5 7] ABSTRACT A circular knitting machine having a needle cylinder is provided with means for cooling the needle cylinder by circulating oil or other cooling medium around an interior part of the needle cylinder and collecting the cooling medium while preventing it from gaining access to the exterior of the needle cylinder.

3 Claims, 3 Drawing Figures PATENTED APR 9 1974 SHEET 2 BF 2 I l I l I I In COOLING SYSTEM FOR NEEDLE CYLINDERS OF CIRCULAR KNITTING MACHINES BACKGROUND OF THE INVENTION This invention relates to circular knitting machines of the independent needle type and is particulary concerned with the problem of overheating in the needle cylinder and knitting elements of such machines.

It is well known that the efficiency ofa machine is impaired, and a rapid deterioration of the knitting elements will most likely take place, when the needle cylinder becomes excessively hot.

The quest for higher production rates has made it necessary to increase the number of knitting stations, and at the same time increase the cylinder speed; consequently increased frictional heat is developed by the knitting elements as they slide up and down in their loop forming movements in the needle cylinder slots or tricks.

Many methods have been used to try to overcome this problem of overheating; for example, by air cooling, oil atomizers blowing on the outside of the needle cylinder, and oil drip feeds which have attempted to lower the temperature of the needle cylinder through increased lubrication, but most have had some undesirable feature which has reduced their efficiency.

SUMMARY OF THE INVENTION The primary object of this invention is to provide a simple and efficient cooling system for the needle cylinders of circular knitting machines, irrespective of whether said cylinders rotate or are stationary.

The invention therefore provides a method of cooling the needle cylinder ofa circular knitting machine, comprising circulating a cooling medium (preferably a cooling liquid) to an interior part only of the needle cylinder. The invention also provides a circular knitting machine including a needle cylinder and having means for circulating a cooling medium to an interior part only of the needle cylinder.

In a circular knitting machine, the needle cylinder may rotate within a cam'box which contains the needleoperating cams or the cam box may rotate about the needle cylinder, the drive being imparted to the cylinder or cam box (as the case may be) by means of driving gearing. According to a subsidiary feature of the invention the cooling medium is also supplied to a gear box containing the driving gearing to lubricate the driving gearing, preferably after leaving the cylinder inter- However under some circumstances, and particularly with high machine speeds and high cylinder working temperatures, it may be preferred to employ a cooling medium which is more suitable as a coolant than as a lubricant. It is therefore within the scope of this invention to circulate the cooling medium in a circuit which excludes the gear box and to lubricate the gearing by other means.

In order that the invention may be better understood the embodiment of the invention preferred at present is described as applied to a machine of the rotary needle cylinder type, such as is commonly employed in the production of ladies hosiery, wherein the cylinder is driven about a verticle axis by driving gears mounted, in a gear box immediately below the cylinder, to rotate about vertical axes. However, it will be understood that the invention is also applicable to such machines in which the cylinder is driven about a verticle axis but in which the driving gears rotate about horizontal axes.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a sectional side elevation of a needle cylinder and gear box of a rotary needle cylinder type knitting machine, showing part of a cooling arrangement;

FIG. 2 is a diagrammatic side view of the machine showing the cooling arrangement and pumping means;

FIG. 3 is a view, in section, looking down along the line 3-3 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1 a needle cylinder 1 is shown rotatably mounted on a non-rotatable cylinder raising tube 2 by means of ball bearings 3 at the upper end of the cylinder and needle bearings 4 at the lower end of the cylinder. The cylinder raising tube 2 is supported by a pivoted trunnion 40 on a pivoted lever 41 and is slidable up and down in bearings 5 and 6 with the needle cylinder 1 when influenced by the conventional stitch length control cams 7 on the control drum 8. Slots 9 cut longitudinally and equi-distant around the outer face of the cylinder raising tube 2 provide locations for cooling fluid delivery tubes 10 which are pressed into the slots and retained by circlips 11. The tubes 10 are flexible to allow the cylinder to be raised and lowered. The lower ends of the fluid delivery tubes are located in a junction block 12 situated in the chamber 13 of the head casting 14. A main cooling fluid delivery tube 15 is connected, from the junction block 12, through a head casting 14 to a delivery pump 16 (FIG. 2). It will be appreciated that in this particular construction the needle cylinder 1 revolves around the non-rotating tube 2 and therefore in order to obtain a smooth flow of cooling fluid within the cylinder a thin walled sleeve 17 is mounted within the bore of the cylinder for rotation therewith and defines an annular chamber 17a between the cylinder and the sleeve. As the cylinder and sleeve 17, together with the cooling fluid, all rotate at the same speed, any undesirable frictional resistances are avoided.

When the pump 16 (FIG. 2) is made to operate by pressing a START button on the machine, the cooling fluid is forced up the delivery tube 15 to the junction block 12. It then divides to pass along the tubes 10 to be forced out of the open ends of the tubes onto the inner face 1a of the needle cylinder 1, so reducing the temperature, before passing out of the annular chamber 17a. The return flow by gravity of the cooling fluid to the chamber 13 in the head casting 14, is somewhat restricted by the attachment of the sleeve 17 to the inner face of the cylinder at regions 18, but a number of longitudinal channels 19 cut on the inside face of the needle cylinder and opening into horizontal ports 19a give passage to the fluid on its return to the chamber 13 in the head casting 14. The described embodiment is designed for use with a lubricating liquid as cooling medium and, therefore, cylinder drive gears (or transmission members) 33, 35 and 36, situated in the chamber 13, are lubricated by the liquid as it is flung from the ports 19a.

ln the chamber 13, the liquid builds up to a certain level before it is drained away by a drain tube 20 (FIG. 2).

The drain tube 20 is connected to a distributor manifold 21 into which the cooling liquid drains before passing into a radiator 22a.

In order that the temperature of the liquid may be reduced, air suction tubes 23 and 24 of a fabric takedown unit of the machine are connected to a chamber 22 housing the radiator 22a to provide air cooling means for the liquid before the latter is circulated again by the pump 16.

After cooling, the liquid passes from the radiator 22a into a collecting manifold 25, before draining down a return tube 26 into a main reservoir 27.

A seal 28 prevents seepage of the cooling liquid onto the upper face of the cover plate 29 and also prevents needle oil draining into and contaminating oil in the gear box. Similar seals are used elsewhere as required.

The machine illustrated in FlG. 1 has a vertical drive shaft 30 which is rotatably mounted in two bearings 31 in the chamber 13. Fixed to the lower end of the drive shaft there is a pulley wheel 32, belt driven from a variable speed motor (not shown).

A drive pinion 33 is keyed to the upper end of drive shaft 30 and is retained by a lock nut 34. Pinion 33 drives an intermediate gear 35, rotatable on a vertical stub shaft 37, and gear 35 drives a gear 36 which is centered in the bore of the cylinder 1 and is fixed to that cylinder by screws 42.

Because the gears are housed in the chamber 13, where the cooling medium is oil, it will be seen that good lubrication of the cylinder drive gears is achieved.

I claim:

1. A circular knitting machine including a needle cylinder having needles held thereby, operating means to operate the needles held by the needle cylinder, drive means to rotate the needle cylinder relative to said perating means, a chamber, and transmission members housed in said chamber and connected between said drive means and said needle cylinder; the improvement comprising a cooling circuit including:

a. said chamber;

b. means for delivering a cooling medium to, and collecting said cooling medium from, the interior part of the needle cylinder to effect cooling thereof;

0. said means including inner and outer cylindrical walls defining an annular return passage therebetween, said cylindrical walls being rotatable with the needle cylinder, the outer cylindrical wall being defined by the inner wall of the needle cylinder;

d. a sleeve co-axially mounted within the needle cyl inder and rotatably connected therewith, said inner cylindrical wall being defined by said sleeve;

e. the cooling circuit being effectively closed in the region of the needle cylinder, whereby cooling medium is prevented from gaining access to the exterior wall of the needle cylinder.

2. A circular knitting machine as claimed in claim 1 wherein means are provided for recirculating the cooling medium collected from the interior of the needle cylinder through the interior of the needle cylinder without gaining access to the exterior of the needle cylinder.

3. A method of cooling a needle cylinder of a circular knitting machine which comprises:

a. delivering to an interior part of the needle cylinder a cooling medium;

b. allowing the cooling medium to effect cooling of the interior part of the needle cylinder;

0. collecting cooling medium from the interior of the needle cylinder; and

recirculating the collected cooling medium through the interior of the needle cylinder while preventing the cooling medium from gaining access to the exterior wall of the needle cylinder. 

1. A circular knitting machine including a needle cylinder having needles held thereby, operating means to operate the needles held by the needle cylinder, drive means to rotate the needle cylinder relative to said operating means, a chamber, and transmission members housed in said chamber and connected between said drive means and said needle cylinder; the improvement comprising a cooling circuit including: a. said chamber; b. means for delivering a cooling medium to, and collecting said cooling medium from, the interior part of the needle cylinder to effect cooling thereof; c. said means including inner and outer cylindrical walls defining an annular return passage therebetween, said cylindrical walls being rotatable with the needle cylinder, the outer cylindrical wall being defined by the inner wall of the needle cylinder; d. a sleeve co-axially mounted within the needle cylinder and rotatably connected therewith, said inner cylindrical wall being defined by said sleeve; e. the cooling circuit being effectively closed in the region of the needle cylinder, whereby cooling medium is prevented from gaining access to the exterior wall of the needle cylinder.
 2. A circular knitting machine as claimed in claim 1 wherein means are provided for recirculating the cooling medium collected from the interior of the needle cylinder through the interior of the needle cylinder without gaining access to the exterior of the needle cylinder.
 3. A method of cooling a needle cylinder of a circular knitting machine which comprises: a. delivering to an interior part of the needle cylinder a cooling medium; b. allowing the cooling medium to effect cooling of the interior part of the needle cylinder; c. collecting cooling medium from the interior of the needle cylinder; and d. recirculating the collected cooling medium through the interior of the needle cylinder while preventing the cooling medium from gaining access to the exterior wall of the needle cylinder. 